Ch. 10 - Biodiversity

Sect. 1 Objectives Describe the diversity of species types on Earth, relating the difference between known numbers and estimated numbers. List and describe three levels of biodiversity. Explain four ways in which biodiversity is important to ecosystems and humans. Analyze the potential value of a single species.

Biodiversity(biological diversity) – the number of different species in a given area Plants Trees, shrubs, flowers, weeds Animals Mammals, insects, fish, crustaceans Fungus Insects Bacteria Etc.

How many are there? 1.7 million species are known Most are insects 10 million species are estimated to exist

Levels of Diversity Species diversity – number of different species in an area Ecosystem diversity – variety of habitats, communities Genetic diversity – number of genes contained in all members of a population

What makes everything different? Genes (DNA) – code for different traits or characteristics that can be inherited Everyone's is different (unless you are an identical twin)

Why is Biodiversity Important? All species are dependant on other species and are depended on by others Everyone fits in the food web/chain If you remove one link, all the others will fall

– one species that many others depend on Keystone species – a species that is critical to the functioning of the ecosystem because it affects the survival and abundance of many other species – one species that many others depend on

Ex: Sea Otters 1. Otters killed for fur 2. Sea urchin population grew 3. Kelp disapeared

Ex: Prairie dogs Their burrows act as homes to other creatures, including burrowing owls, badgers, rabbits, black-footed ferrets, snakes, salamanders, and insects.Their burrowing activity works to loosen and churn up the soil, increasing its ability to sustain plant life.Their foraging and feeding practices enable a more nutritious, diverse and nitrogen-rich mixture of grasses and forbs (broad-leafed vegetation) to grow.The enriched vegetation attracts an amazing array of wildlife who graze in their colonies.Black-tailed prairie dogs play an integral role in the prairie food chain; they are a critical food source for such animals as the endangered black-footed ferret, swift fox, coyotes, hawks, eagles and badgers.

Biodiversity and Survival More genetic diversity means the population has a greater chance of surviving environmental changes. (ie: global warming) Ex: Hemophilia

Biodiversity and Humans More organisms the more things for us Food Antibiotics Clothing Shelter Chemicals

Ecotourism – tourism that supports the conservation and sustainable development of ecologically unique areas Has become very popular lately

Sect. 2 Objectives Define and give examples of endangered and threatened species. Describe several ways that species are being threatened with extinction globally. Explain which types of threats are having the largest impact on biodiversity. List areas of the world that have high levels of biodiversity and many threats to species. Compare the amount of biodiversity in the United States to that of the rest of the world.

All species are considered one of these: depending on their natural numbers Extant Threatened Endangered Extinct

Extant – living animals

Threatened – still abundant in its natural habitat but is likely to become endangered because of their declining numbers                                      

Endangered – so few individuals that they are likely to become extinct

Extinct – no known individuals still alive

Species most at risk Animals that are more likely to become extinct are those that: Have small populations Migrate Need large or special habitats Are exploited by humans Currently humans are the greatest cause of extinctions!

Species can be threatened by Humans Hunting Loss of habitat (75% of current extinctions) Deforestation Damming Burning Growing cities Pollution Poaching Invasive species Natural Causes Interbreeding Natural Disaster Disease

Exotic – not native to an area When brought to a new area exotic species can cause the extinction of other species they out compete Ex: Fire Ant Horny Toads (Desert Horned Lizard) eat ants Fire ants (exotic species) kill horny toads. Horny toads are now threatened!

Generalist Species Species with a broad niche, can survive in many different places HUMANS Often are invasive species

Specialist Species Species with a narrow niche. Only live in a small range of environmental factors Fewer if these because they can become extinct more readily

Critical Areas Tropical Rain Forests – over half the worlds species live here Most species have not been named, yet But, lots of these are disappearing Due to habitat destruction by humans! Coral Reefs and Coastal areas Islands – why?

Biodiversity Hotspots – high number of endemic species but are threatened by humans

Madagascar Biodiversity Hotspot Endemic Species 80% of plants 91% of reptiles 100% of lemurs (10% of worlds primate population) Only 18% of the original forests remain!!

Sect. 3 Objectives List and describe four types of efforts to save individual species. Explain the advantages of protecting entire ecosystems rather than individual species. Describe the main provisions of the Endangered Species Act. Discuss ways in which efforts to protect endangered species can lead to controversy. Describe three examples of worldwide cooperative efforts to prevent extinctions.

Ch. 10 Ecolog Read in your book, in Sect. 3, about the following ways to save species. In your Ecolog write a brief description of each! Captive-Breeding programs Preserving Genetic Material Zoos, etc. Conservation Strategies Write a paragraph about why it is important to save species and the biodiversity around the world.